In gas turbine engines, mixtures of fuel and gas are combusted within a combustor disposed upstream from a transition piece and a turbine. The combustor produces high energy fluids from which mechanical energy can be derived for the generation of power and electricity. The high energy fluids are continually reused until significant levels of power generation cannot be derived at which point they are exhausted into the atmosphere. This exhaust often includes pollutants produced during the combustion, such as nitrous oxides (NOx) and carbon monoxide (CO).
Efforts have been expended to reduce the amount of pollutants produced by the combustion processes and include the development of LLI. LLI involves the injection of combustible materials into the flow of the high energy fluids at a location downstream from the normal combustion zone in the combustor. This downstream location could be defined as a section of the combustor liner or at a section of the transition piece. In any case, the combustible materials injected at this location increase the temperature and energy of the high energy fluids and lead to an increased consumption of CO with little to no significant increase in NOx for reasonable levels of LLI fuel flow.